Field of the Invention
The present invention relates in general to the field of information handling system information communication, and more particularly to an information handling system differential signaling variable bandwidth interface.
Description of the Related Art
As the value and use of information continues to increase, individuals and businesses seek additional ways to process and store information. One option available to users is information handling systems. An information handling system generally processes, compiles, stores, and/or communicates information or data for business, personal, or other purposes thereby allowing users to take advantage of the value of the information. Because technology and information handling needs and requirements vary between different users or applications, information handling systems may also vary regarding what information is handled, how the information is handled, how much information is processed, stored, or communicated, and how quickly and efficiently the information may be processed, stored, or communicated. The variations in information handling systems allow for information handling systems to be general or configured for a specific user or specific use such as financial transaction processing, airline reservations, enterprise data storage, or global communications. In addition, information handling systems may include a variety of hardware and software components that may be configured to process, store, and communicate information and may include one or more computer systems, data storage systems, and networking systems.
Information handling systems communicate information with external devices and networks to provide a number of different functionalities. For example, information handling systems send graphics information to displays to present visual images, to speakers to play audible noise, to human interfaces devices (HID) to accept inputs to keys or pointing inputs, and to network interfaces to communicate with networks. Although wireless interfaces support many such communications, wired communications tend to have greater security and speed. Wired interfaces typically couple with information handling systems through standardized ports, such as Universal Serial Bus (USB), Ethernet, HDMI, DisplayPort and other types of ports defined by various standards bodies. By limiting the number of different types of ports and cable connectors to a set of well-defined standards, information handling system manufacturers provide greater convenience to end users.
USB in particular has gained popularity as a standardized serial interface for information handling systems. USB generally supports HID devices that plug into an information handling system cable, such as keyboards or mice. Many peripheral devices include USB interfaces to allow flexibility in interactions with information handling systems. Examples include external storage devices, cameras, smartphones, tablets, printers, displays, docking stations, etc. Although conventional USB provides good bandwidth for data communications through serial interfaces and differential signaling, functions that use high rates of communications are often limited when performed over USB. For example, USB will support a cable interface with a display device, however, the display quality may suffer at higher resolutions due to limitations in bandwidth relative to display-specific ports and cables, such as DisplayPort.
In part to address the need for higher bandwidth through a standardized serial interface, industry has introduced USB 3.0 with an increased bandwidth provided by 8 pins supporting 4 differential signaling pairs. USB 3.0 not only increases data transfer rates but also increases power transfer rates with a new connector and port configuration known as the Type C connector. To help drive adoption of USB 3.0 and the Type C connector, the USB standards body allows the use of “guest” protocols on the 4 differential signaling pairs. The standard includes provisions for communication and configuration of the 8 pin interface such that the host and supported device can find a mutually acceptable communication channel. Thus, rather than “tunneling” display pixel data through a USB interface, two of the differential pairs may be configured as DisplayPort pairs to support “2 k” resolution display devices or four of the differential pairs may be configured as DisplayPort pairs to support high resolution “4 k” display devices. By allowing flexible use of differential pairs for different types of protocols, the USB standards body provides a common cable configuration that adapts to different types of functions. Nonetheless, the bandwidth at the USB 3.0 Type C connector is constrained by the definition of 8 pins that support 4 differential pairs.